Public opinion, of course, is a critical factor affecting efforts to address global warming. While there are numerous factors shaping public opinion, and it is a complex subject, research suggests there are at least three key factors contributing to perspectives on climate change and environmentalism.

The second is the degree to which a person is egalitarian versus individualistic. Those who are more egalitarian, believing in collective efforts to find solutions that are good for all people, tend to be more apt to believe in climate change and to want to do something about it. Those who are more individualistic, believing individuals ought to be free from collective efforts or interventions, tend to be less apt to see climate change as an issue (Read more about that here, see page 5). Of course, these characteristics also play a role in one's political perspectives and ultimately political identity, which can limit one's ability to fairly consider viewpoints which deviate from the norm of the party with whom the person identifies.

The third key factor is the amount of attention paid to global warming and education on the topic. Those who have not studied the issue in earnest tend to be less likely to accept climate change as a major issue, or to acknowledge it is caused by humans. (More here, see page 5).

Seven in ten Americans (70%) think global warming is happening, which nearly matches the highest level in our surveys (71%), recorded in 2008.

By contrast, only about one in eight Americans (13%) think global warming is not happening.

Americans are also more certain global warming is happening – 46% are “extremely” or “very” sure it is happening, its highest level since 2008. By contrast, far fewer – 7% – are “extremely” or “very sure” global warming is not happening.

Over half of Americans (58%) understand that global warming is mostly human caused, the highest level since our surveys began in November 2008. By contrast, three in ten (30%) say it is due mostly to natural changes in the environment – the lowest level recorded since 2008.

Only about one in eight Americans (13%) understand that nearly all climate scientists (more than 90%) are convinced that human-caused global warming is happening.

Over half of Americans (57%) say they are at least “somewhat worried” about global warming. About one in six (17%) are “very worried” about it.

Six in ten Americans (59%) think global warming is affecting weather in the United States, and half think weather is being affected “a lot” (25%) or “some” (27%).

About one in three Americans (35%) think people in the U.S. are being harmed by global warming “right now.”

Most Americans think global warming is a relatively distant threat – they are most likely to think that it will harm future generations of people (71%), plant and animal species (71%), the Earth (70%), people in developing countries (62%), or the world’s poor (62%). They are less likely to think it will harm people in the U.S. (58%), their own grandchildren (56%) or children (50%), people in their community (48%), their family (47%), themselves (43%), or members of their extended family living outside the U.S. (41%).

Four in ten Americans (39%) think the odds that global warming will cause humans to become extinct are 50% or higher. Most Americans (58%) think the odds of human extinction from global warming are less than 50%.

Four in ten Americans (40%) say they have personally experienced the effects of global warming, six in ten (60%) say they have not.

Only one in three Americans (33%) discuss global warming with family and friends “often” or “occasionally,” while most say they "rarely" or "never" discuss it (67%). Additionally, fewer than half of Americans (43%) hear about global warming in the media at least once a month, and only one in five (19%) hear people they know talk about global warming at least once a month.

Six in ten Americans (63%) say the issue of global warming is either “extremely” (10%), “very” (16%), or “somewhat” (38%) important to them personally. Four in ten (37%) say it is either “not too” (22%) or “not at all” (15%) important personally.

• Half of Americans say they have thought “a lot” (18%) or “some” (31%) about global warming. The other half say they have thought about global warming just “a little” (33%) or “not at all” (17%).

By a large margin, Americans say that schools should teach children about the causes, consequences, and potential solutions to global warming (78% agree vs. 21% who disagree).

Four in ten Americans (42%) say their family and friends make at least "a moderate amount of effort" to reduce global warming. A similar number (45%) say it is at least "moderately important" to their family and friends that they take action to reduce global warming.

The most common reason why Americans want to reduce global warming is to provide a better life for our children and grandchildren – a reason selected by one in four Americans (24%). The next most common reasons are preventing the destruction of most life on the planet (16%) and protecting God's creation (13%).

Few Americans are optimistic that humans will reduce global warming. Nearly half (48%) say humans could reduce global warming, but it’s unclear at this point whether we will do what is necessary, and nearly one in four (24%) say we won’t because people are unwilling to change their behavior. Only 7% say humans can and will successfully reduce global warming.